A control system for a vehicle, the control system having one or more controllers, the control system being arranged to: determine a likelihood of a NOx adsorber trap of a vehicle requiring purging; determine an efficiency of purging the NOx adsorber trap; determine an operating efficiency of a selective catalyst reduction system of the vehicle; determine a schedule for purging of the NOx adsorber trap of the vehicle in dependence on the likelihood of the NOx adsorber trap requiring purging, the efficiency of purging the NOx adsorber trap, and the operating efficiency of the selective catalyst reduction system; and control purging of the NOx adsorber trap according to the schedule.

A system includes a catalyst for receiving and treating exhaust gas generated by an engine, a passive NOx adsorber (PNA) positioned upstream of the catalyst, a bypass valve positioned upstream of the catalyst and the PNA, and a controller. The controller is configured to, determine that the catalyst is operating under cold start conditions, control the bypass valve to direct exhaust gas to the PNA, determine that the catalyst is no longer operating under cold start conditions and continue to control the bypass valve to direct exhaust gas to the PNA for a predetermined duration, and after the elapse of the predetermined duration, control the bypass valve to direct exhaust gas to the catalyst bypassing the PNA. The controller is also configured to detect a high transient torque demand while the exhaust gas is provided to the PNA, and split the torque demand between the engine and an electric motor.

An internal combustion engine (1), with an engine regulating device (3) and an exhaust gas aftertreatment device (16) with an SCR catalytic converter (4) for the reduction of at least one NO.sub.x component, and with a catalytic converter regulating device (6), wherein the engine regulating device (3) is prescribed a target value for an NO.sub.x mean value of the NO.sub.x component of the exhaust gases, which mean value results at an outlet point (7) of the exhaust gas aftertreatment device (16) in relation to a predefinable time period, and the engine regulating device (3) is configured at least in one operating mode to continuously calculate an NO.sub.x reference value for the catalytic converter regulating device (6) with consideration of No.sub.x components which have already been emitted and the predefined target value, which reference value is selected in such a way that the predefined target value results at the outlet point of the exhaust gas aftertreatment device (16) at the end of the predefinable time period when the calculated NO.sub.x reference value of the catalytic converter regulating device (6) is fed as NO.sub.x setpoint value to the regulating means.

Various embodiments include methods for determining the efficiency of an SCR catalytic converter in a system including a nitrogen oxide sensor, and a metering device for a reducing agent arranged in an exhaust-gas duct, and an exhaust recirculation line with a recirculation valve disposed downstream of the SCR catalytic converter and feeding an intake region of the engine. The methods comprise: setting or identifying a quasi-steady-state operating state and an associated recirculation rate; adding a first quantity of reducing agent using the metering device; measuring a resulting first nitrogen oxide value using the sensor; adding a further predefined quantity, different from the first quantity; measuring the resulting nitrogen oxide values using the sensor; and determining the efficiency of the SCR catalytic converter based at least in part on the associated exhaust-gas recirculation rate and the measured nitrogen oxide values.

A vehicle system (100) includes a conversion catalyst (116), a temperature sensor (156), an indication device (142), and an exhaust gas aftertreatment system controller (132). The conversion catalyst (116) is configured to receive exhaust gas. The temperature sensor (156) is configured to sense a conversion catalyst temperature of the conversion catalyst (116). The indication device (142) is operable between a static state and an impure fuel alarm state. The exhaust gas aftertreatment system controller (132) is configured to receive the conversion catalyst temperature from the temperature sensor (156). The exhaust gas aftertreatment system controller (132) is also configured to compare the conversion catalyst temperature to a conversion catalyst temperature lower threshold. The exhaust gas aftertreatment system controller (132) is also configured to compare the conversion catalyst temperature to a conversion catalyst temperature upper threshold.

Systems and methods for controlling a dosing of reductant for an internal combustion engine system including a catalyst are disclosed. The method includes measuring a value indicative of inlet temperature of the catalyst. When the inlet temperature is less than or equal to a first threshold, the method includes adjusting the dosing of reductant according to a first process. When the inlet temperature is greater than the first threshold, the method includes adjusting the dosing of reductant according to a second process, the second process being different than the first process.

A gas sensor system is equipped with a first gas detection unit, and a second gas detection unit. The first and second gas detection units include a gas introduction port for introducing a gas to be measured, a measurement chamber communicating with the gas introduction port, a conversion medium (NH.sub.3 oxidation catalyst) arranged between the gas introduction port and the measurement chamber, and which converts a portion of a first gas type into a second gas type, and a detection device that detects the second gas type. A ratio of diffusion resistances of the first gas detection unit and the second gas detection unit is greater than or equal to 0.71 and less than or equal to 1.4.

A vehicle system (100) includes a conversion catalyst (116), a temperature sensor (156), an indication device (142), and an exhaust gas aftertreatment system controller (132). The conversion catalyst (116) is configured to receive exhaust gas. The temperature sensor (156) is configured to sense a conversion catalyst temperature of the conversion catalyst (116). The indication device (142) is operable between a static state and an impure fuel alarm state. The exhaust gas aftertreatment system controller (132) is configured to receive the conversion catalyst temperature from the temperature sensor (156). The exhaust gas aftertreatment system controller (132) is also configured to compare the conversion catalyst temperature to a conversion catalyst temperature lower threshold. The exhaust gas aftertreatment system controller (132) is also configured to compare the conversion catalyst temperature to a conversion catalyst temperature upper threshold.

The present invention is directed to a method of preparing a synthetic crystalline material, designated as JMZ-12, with a framework built up by the disorder AEI and CHA structures, substantially free of framework phosphorous and prepared preferably in the absence of halides such as fluoride ions. Such method comprises the step of heating a reaction mixture under crystallization conditions for a sufficient period to form a disordered zeolite having both CHA and AEI topologies, wherein the reaction mixture comprises at least one source of aluminum, at least one source of silicon, a source of alkaline or alkaline-earth cations, and a structure directing agent containing at least one source of quaternary ammonium cations and at least one source of alkyl-substituted piperidinium cations in a molar ratio of 0.20 to about 1.4. The resulting zeolites are useful as catalysts, particularly when used in combination with exchanged transition metal(s) and, optionally, rare earth metal(s).

The present disclosure relates to a method for determining urea feeding in an exhaust gas aftertreatment system (100,200), the exhaust gas aftertreatment system (100,200) being connectable to an internal combustion engine (101,201) operating under an engine operating condition, the system (100,200) comprising a first Selective Catalytic Reduction (SCR1) system comprising a first selective reduction catalyst (SCR1c) and a first doser (103,203) configured for feeding urea upstream the SCR1 system, at least one Particulate Filter (PF) downstream the SCR1 system or as a substrate for the SCR1c and a second Selective Catalytic Reduction (SCR2) system downstream the PF, the SCR2 system comprising a second selective reduction catalyst (SCR2c) and a second doser (104,204) configured for feeding urea upstream the SCR2c, the method comprising the steps of estimating the amount of particles in the PF; and determining the amount of urea to be fed by the respective first and second doser (4,5) based on the engine operating condition and such that: a) the amount of particles in the PF is within a predefined particle amount range, and, b) the NOx level of the exhaust gas exiting the SCR2 system is within a predetermined NOx level range. The present disclosure also relates to an exhaust gas aftertreatment system (100,200) and a vehicle comprising the exhaust gas aftertreatment system (100,200), a computer program comprising program code means for performing the steps of the method, a computer readable medium carrying a computer program comprising program code means for performing the steps of the method and a control unit for controlling urea feeding in the exhaust gas aftertreatment system (100,200).